Plastic bottles can be formed from plastic film. One or more elongated webs of the plastic film are unrolled from spools, and are severed into panels that are folded and seamed together to form structures known as a preforms. Each preform corresponds to an individual bottle. A fitment may be installed in the neck of a preform to provide a spout, but the preform has a generally flat shape defined by the flat panels of plastic film. The preform is then placed inside a blow-molding cavity that has the shape of the bottle, and is expanded under fluid pressure inside the cavity. This deflects the flat sections of plastic film into the shape of the bottle.